Provincial port integration effects on port development: A novel synthetic control investigation of Zhejiang, China

Provincial port integration (PPI) is the mainstream trend of China's regional port reform and upgrading, which influences the entire port system. The synthetic control method (SCM) is first used in this study to analyze the effect of PPI on port container throughput (PCT) that signals port development to some extent in Zhejiang Province, with nine other provinces that have not implemented PPI from 2004 to 2018 as the control objects. Further, to identify the transmission mechanism by which PPI affects PCT, datasets related to port development spanning 2004–2020 are collected from 16 provincial administrative regions in China. On this basis a mediation effect model including both the parallel and serial mediations is developed. Results show that PPI has contributed to the significant improvement of PCT in Zhejiang, increasing its contributions over time. The exploration of the transmission mechanism indicates that PPI can indirectly promote port development mainly through the compound mediating effect of port efficiency improvement, industrial structure upgrading and foreign trade growth. The findings may provide productive guidelines for the integration and coordinated development of regional port clusters and can also be generalizable to other countries or maritime ranges worldwide.